test class to test lists of potentials and MWPotential in particular, work towards #150
test class to test lists of potentials and MWPotential in particular, work towards #150

followthesheep/galpy,followthesheep/galpy,followthesheep/galpy,jobovy/galpy,jobovy/galpy,jobovy/galpy,jobovy/galpy,followthesheep/galpy